Search PubMed⌕ Search

Biomedical subjects

T Iijima

Publications and source records attributed to T Iijima.

At least 271 records · Page 15Linked to original sources
PubMed1993

Correlation between peri-infarct DC shifts and ischaemic neuronal damage in rat.

The effect of peri-infarct depolarizations on ischaemic injury was studied in rats submitted to 3 h occlusion of the left middle cerebral artery (MCA). The number of depolarizations varied from 1 to 8 and infarct volume from 37 to 159 mm3. The correlation between the two variables revealed a highly significant linear relationship (r = 0.800; p < 0.005), each depolarization accounting for an increase in infarct volume by about 13 mm3. The aggravating effect of repeated depolarizations was also demonstrated by the gradual increase in cortical DC shift duration, in EEG amplitude recovery time, and in EEG delta power with increasing number of depolarizations. Suppression of peri-infarct depolarizations is a rational approach for reducing the severity of ischaemic stroke.

Animals↗
PubMed1993

Microglial reaction in the rat cerebral cortex induced by cortical spreading depression.

The response of microglial cells to cortical spreading depression (CSD) was studied in rat brain by immunocytochemistry. CSD was elicited for one hour by the topical application of 4M potassium chloride solution and the microglial reaction examined immunocytochemically after 4, 16, 24 and 72 hours. CSD was sufficient to induce a microglial reaction throughout the cortex at 24 hours. Activated microglial cells furthermore showed a striking de-novo expression of major histocompatibility complex class II antigens. In contrast, no microglial reaction was observed in the cortex of sham-operated animals. This microglial reaction in response to CSD was not associated with histologically detectable neuronal damage. These results support the view that microglial cells are extremely sensitive to changes of the brain microenvironment. Their activation may be related to changes of ion homeostasis in the brain which are not sufficient to trigger neuronal injury.

Animals↗
PubMed1993

Expression of the ligand-binding domain-containing region of retinoic acid receptors alpha, beta and gamma in Escherichia coli and evaluation of ligand-binding selectivity.

The complete molecule or the ligand-binding domain-containing region of each of the three subtypes of human retinoic acid receptors (hRAR alpha, hRAR beta and hRAR gamma) was expressed in Escherichia coli. The expressed recombinant RARs (rRARs: rRAR alpha/E, rRAR beta/E and rRAR gamma) showed nearly the same magnitude of binding affinity toward [3H]retinoic acid (RA) as hRARs extracted from human cells (Ka values: 6.0 x 10(9) M-1 for rRAR alpha/E and 2.7 x 10(10) M-1 for both rRAR beta/E and rRAR gamma). Therefore, the ligand-binding selectivity of the rRARs toward RA and synthetic retinoids (4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenylcarbamoyl )benzoic acid (Am80), (E)-4-[3-(3,5-di-tert-butylphenyl)-3-oxo-1-propenyl]benzoic acid (Ch55)) was examined. Am80 bound rRAR alpha/E preferentially and showed no binding activity toward rRAR gamma, which is consistent with the case of hRAR gamma. Ch55 bound all three subtypes of rRARs, preferentially rRAR beta/E. These results suggest that the intrinsic nature of the binding of each retinoid can be investigated by usage of the rRARs. However, rRARs show quantitatively different ligand-selectivity from that of hRARs: RA showed higher binding affinity toward rRARs than both Am80 and Ch55, but Ch55 binds all three subtypes of hRARs stronger than RA and Am80, which binds hRAR beta stronger than RA.

Base Sequence↗
PubMed1993

[A case of primary systemic amyloidosis with skeletal muscle atrophy and congestive heart failure].

A 77-year-old male had been noticing progressive weakness of the legs for three years. By the age of 75 he had difficulty in climbing stairs. On admission, serum level of CPK was moderately high. There were weakness and atrophy of the proximal muscles. Deep tendon reflexes were depressed. Sensation was normal. The electromyogram and the biopsy of the femoral quadriceps muscles showed nonspecific changes. In 1989, he developed difficulty in walking and had congestive heart failure. On the second admission, moist rales were heard over the chest, and pitting edema was present in the lower extremities. The chest roentgenogram showed a cardiothoracic ratio of 63% and bilateral pleural effusion. The electrocardiogram showed atrial flutter with 2:1 conduction, QS in V1-3, rS in V4, and ST depression and T inversion in V5,6. The echocardiogram revealed a thick left ventricular wall and impaired left ventricular contraction (EF 22%). Macroglossia, hepatosplenomegaly and renal dysfunction were not noted. Congestive heart failure progressed and he suddenly died of ventricular tachycardia in December 1989. At autopsy, skeletal muscle fibers varied in size and showed fiber splitting. A cellular infiltration was observed in the stroma. Amyloid deposit was positively stained with Congo red. The heart weight was 570 g with marked left ventricular hypertrophy and moderate bilateral atrial dilatation. In both atria and ventricles, extensive amyloid deposition was found around myocardial fibers as well as in perivascular spaces. Amyloid was present also in the liver, the kidneys, the gastrointestinal tracts, and the other organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[The significance of preoperative chemotherapy for thermopreservation of limbs].

Preoperative chemotherapeutic effects on 42 osteosarcomas treated with CDDP intra-arterial infusion protocol were compared with the effects of treatment of same by local perfusion only, following administration of adriamycin (ADR) or high doses methotrexate and leucovorin (HD-MTX). Thirteen cases were further given local hyperthermic perfusion (LHP) treatment. The preoperative local treatment resulted in a poor response in cases in which the serum ALP failed to fall down the normal range, those with angiographically demonstrated tumor stains remaining, and those with reactive zones remaining as indicated by T2 MR imaging. The ratios of necrotic areas were significantly higher in the LHP group, while those of viable areas were significantly lower in the LHP group compared to other groups. Total tumor cell killing was possible in six of 13 cases in the LHP group. Post-necrotic fibrosis and post-necrotic osteosclerosis were significantly higher in the LPH group. The results suggested that, in selected cases treated with LHP, conservative surgery may well be possible so as to preserve all functional activity.

Adolescent↗
PubMed1993

[Effect of extended thymectomy in myasthenia gravis of pure ocular type].

The effect of extended thymectomy in myasthenia gravis of pure ocular type was investigated in 13 patients, who were divided into the surgical group of nine and the conservative group of four. In the surgical group, the onset was at 47 +/- 20 years old. The preoperative duration of symptoms was 4 +/- 6 years. The age at the time of operation was 51 +/- 16 years old. Three patients had thymomas, including one malignant thymoma. Acetylcholine receptor antibody titer was over normal range with 34.0 +/- 49.7 nmol/l. No postoperative crisis occurred. The palliation rate of the surgical group was more higher through the whole period than that of the conservative group, and increased with progress of the course. The remission occurred in the surgical group, but did not in the conservative group. It took 7 months to improve the symptom in the surgical group, while 18 months in the conservative group. We conclude extended thymectomy is reasonable for patients with myasthenia gravis of pure ocular type.

Adult↗
PubMed1993

[Production of monoclonal antibodies against osteoclasts of rat].

In mammals, it has been difficult to collect the authentic osteoclasts on a large scale. Recently we established a culture system for forming osteoclast-like multinucleated cells (MNCs) which exhibited many characteristics of osteoclasts. MNCs instead of authentic osteoclasts were used as immunogen to establish the hybridomas which secrete monoclonal antibodies against the osteoclasts by in vitro immunization. We obtained two monoclonal antibodies, HOK 1 and HOK 2. HOK 1 showed intense immunoreactivity with MNCs, mononuclear cells and putative migratory traces of MNCs on the culture dishes, but it had weak reactivity with the stromal cells. HOK 2 also showed strong reactivity with MNCs, mononuclear cells, and the very limited area of the culture dishes just facing to one side of some MNCs. The stromal cells were faintly stained with HOK 2. In th paraffin sections of tibiae, both antibodies intensely stained osteoclasts, osteoblasts and osteocytes. The bone matrix was weakly stained by HOK 2 but not by HOK 1. The present observations indicated that HOK 1 and HOK 2 could recognize the common antigen expressed on cells both involving in the bone formation and resorption. The antigens recognized by HOK 1 and HOK 2 were shown to exist on the putative traces of motile MNCs. These antibodies would be available to investigate the mechanisms of the 'bone remodeling' as a functional marker of bone cells.

Animals↗
PubMed1993

A case of hematophagic histiocytosis associated with acute renal failure.

The present report describes a rare case of hematophagic histiocytosis associated with acute renal failure. A 32-year-old woman was referred to us from a local hospital because of progressive deterioration of renal function, jaundice and a bleeding tendency. The physical findings at admission revealed hyperemic conjunctivae, gingival bleeding, hepatomegaly, and generalized myalgia. Laboratory data indicated a decrease in platelet count, azotemia and hyperbilirubinemia. Marked elevation of serum triglycerides and ferritin was also noted. Histiocyte proliferation with phagocytosis of erythrocytes and platelets was observed in a bone marrow aspirate. A renal biopsy specimen exhibited lesions generally observed in acute tubular necrosis: degeneration and necrosis of tubular epithelial cells; round cell infiltration and edema in the interstitium; and unremarkable glomeruli. The serum titer to coxsackievirus B1 rose from < 4x at admission to 16x after recovery from the illness, suggesting that this virus may have been the causal organism of the accompanying infection. The patient's symptoms improved rapidly with supportive therapy, and complete restoration of renal function was achieved in 20 days. The morphological characteristics of the bone marrow aspirate and the clinical course were compatible with hematophagic histiocytosis.

Acute Kidney Injury↗
PubMed1993

[Cor triatriatum with situs inversus totalis: a case report of an infant].

Cor triatriatum associated with situs inversus is rare. A 6-month-old male who had cor triatriatum with atrial septal defect (ASD) and situs inversus totalis was successfully operated. Urgent surgical intervention was performed because of congestive cardiac failure despite drug therapy. The abnormal septum in the left atrium was resected and ASD was closed. His postoperative course has been uneventful.

Cardiac Catheterization↗
PubMed1993

Structure and pathogenesis of plexiform lesion in pulmonary hypertension.

Plexiform lesions are a characteristic vascular change of pulmonary arteries in pulmonary hypertension. Autopsy of lungs from 28 patients with primary pulmonary hypertension were examined to clarify the nature of the plexiform lesions. Histological studies showed that the plexiform lesions, were usually related to fibrous occlusion at the peripheral sites of pulmonary arteries. To clarify the topographic correlation between the arterial occlusion and plexiform lesions a three dimensional analysis of the pulmonary arteries was performed with a computerized image analyzer. The plexiform lesions were located in the small supernumerary branches which were raised at more proximal sites than the occlusive lesions of their parent pulmonary arteries. An electron microscopic study demonstrated that the arterial branches were severely injured and developed into aneurysm-like dilatation with organization. Within the organized arterial branches, endothelial cells proliferated to form complicated capillary-like channels, which is a feature of the plexiform lesion. From these findings the following process may be considered in pulmonary hypertension: the occlusive changes of peripheral pulmonary arteries may induce a by-pass in the proximal supernumerary branches which are severely affected by increased shear stress and ultimately organized. As a result of the organizing, proliferation of endothelial cells may produce plexiform lesions in the special branches of pulmonary arteries.

Endothelium, Vascular↗
PubMed1992

A clinicopathological and immunohistochemical study of osteofibrous dysplasia, differentiated adamantinoma, and adamantinoma of long bones.

A clinicopathological and immunohistochemical study of 12 cases of osteofibrous dysplasia (OFD), two cases of differentiated adamantinoma, and five cases of adamantinoma of long bones is presented. Although OFD and differentiated adamantinoma showed similar radiologic findings, differentiated adamantinoma was more likely to be a recurrent lesion than osteofibrous dysplasia and seemed to require a more extensive surgical procedure. Immunohistochemically, cytokeratin- and vimentin-positive cells were seen in both OFD and differentiated adamantinoma. The positive cells were scattered in the former, and were both scattered and nest-like in the latter. Both these lesions, however, were negative for epithelial membrane antigen. Excluding two cases of Ewing-like adamantinoma, the other three cases of adamantinoma were also positive for cytokeratin and vimentin. These results suggest that these three lesions share the same histogenetic origin. The two cases of Ewing-like adamantinoma differ from tibial adamantinoma in their radiological, histological and immunohistochemical aspects, and seem to constitute a distinct variant of adamantinoma with a different histogenesis.

Adolescent↗
PubMed1992

Pharmaceutical characterization of corticosteroid suppository treatment for ulcerative colitis.

The dose and method of administration of a corticosteroid given for the treatment of patients with ulcerative colitis are determined according to the range of the diseased area and its severity. In this study, we prepared a hydrophilic suppository consisting of water-soluble prednisolone sodium succinate (PSL-SS) and a hydrophilic base, polyethylene glycol (PEG), and a hydrophobic suppository consisting of water-insoluble prednisolone (PSL) and a hydrophobic base, Witepsol (WT). We determined the spread of the drugs after intrarectal administration and their therapeutic effect. When rats received the hydrophilic suppository, the drug spread farther oral than when they received the hydrophobic suppository. Moreover, more than half of the PSL-SS recovered was observed to have changed into PSL. A therapeutic effect on the colitis induced in rats by acetic acid was noted in the area up to 10 cm from the anus in the case of the hydrophilic suppository, while the effect of the hydrophobic suppository was seen only in the area up to 2.5 cm from the anus. In patients with ulcerative colitis, the hydrophilic suppository showed retrograde spread to a site 34.4 +/- 5.3 cm from the anus, while the hydrophobic suppository spread to a site 19.0 +/- 2.4 cm from the anus. These results suggest that a hydrophobic suppository should be used for patients in whom inflammation is confined to the rectum, and a hydrophilic suppository used for patients in whom inflammation reaches the rectum and the middle part of the sigmoid colon.

Administration, Oral↗
PubMed1992

A pathological and immunohistological case report of fatal infectious mononucleosis, Epstein-Barr virus infection, demonstrated by in situ and Southern blot hybridization.

We present an autopsy case of 20-month-old boy who had a fulminant course of infectious mononucleosis, with severe hepatic failure. Autopsy revealed marked infiltration of immunoblasts in the lymph nodes, liver, spleen, thymus and kidneys. We identified a large number of Epstein-Barr virus (EBV) genomes in the immunoblasts of the lymph nodes, liver and spleen by in situ hybridization. EBV genomes were also detected in the liver and spleen by Southern blot hybridization. Histology of the liver revealed diffuse feathery degeneration of the hepatocytes. However, EBV genomes were not detected in the hepatocytes by in situ hybridization and monoclonal antibody studies. Immunostaining of the autopsy liver specimen revealed a large number of suppressor/cytotoxic T cells (Leu2a positive) in the portal areas and of natural killer (NK) cells (Leu7 positive) in the portal areas and sinusoids of the liver. We therefore suggest that the hepatocellular damage was not caused by the viral replication in the hepatocytes but was mainly caused by the abnormal killer cell activity of the suppressor/cytotoxic T cells and NK cells.

Blotting, Southern↗
PubMed1992

Synaptic activation of rat adrenal medulla examined with a large photodiode array in combination with a voltage-sensitive dye.

The adrenal medulla is innervated by sympathetic preganglionic nerve fibers in the splanchnic nerve. Synaptic activation of the adrenal medulla causes catecholamine secretion which is known to be modified by various neuropeptides and other factors. To understand the neuronal control mechanism of catecholamine secretion, it is necessary to know the transfer function at the synapse and how it is affected by such factors. By using a large photodiode array in combination with a voltage-sensitive dye, membrane potential changes in a slice of the rat adrenal gland were recorded upon brief local electrical stimulation. Electrical signals were recorded only on the portion of the diode array corresponding to the medulla. In a typical record, a spike and an underlying slow potential were observed following a small deflection due to a presynaptic nerve action potential. Both the spike and slow potential were blocked in Ca(2+)-free solution or by hexamethonium, a nicotinic antagonist, but were not affected by atropine, a muscarinic antagonist. The slow potential was interpreted as a nicotinic synaptic potential in the chromaffin cells and the spike as a population action potential. A double pulse experiment revealed that the chromaffin cell action potential began to fail only when the stimulus interval was less than 50 ms (20 Hz). When the stimulus intensity was reduced, the minimal response was found to behave in an all-or-none fashion. This suggested that one nerve fiber is innervating a cluster of chromaffin cells, which may correspond to a previously histologically identified "complex" of cells [Hillarp (1946) Acta. anat. 4, Suppl. 1]. Each complex was innervated by approximately four nerve fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗